Process for preparing 5-(2-{[6-(2,2-difluoro-2-phenylethoxy)hexyl]amino}-1(r)-hydroxyethyl)-8-hydroxyquinolin-2(1h)-one via a novel intermediate

摘要

The present invention is concerned with a compound of formula (Ap) or a pharmaceutically acceptable salt thereof,
wherein P 1 represents a hydroxy protecting group and P 3 represents an amino protecting group. The present invention is also related to a process for preparing a compound of formula (I) or any pharmaceutically acceptable salt thereof, via a novel intermediate compound (Ap).